Elias Groot
Software Lead, Project Administrator
Pipeline
A pipeline is a collection of services that are meant to run together. Within a pipeline, services communicate by sending and receiving data over streams. There can only be one pipeline per Rover, which is managed and executed by roverd.
Validation
A pipeline is considered valid if:
- There is at least one service enabled
- Each service has a unique name
- If a service uses an alias, no two services use the same alias, and no alias to a different, enabled service is enabled
- For each service, all of its input streams can be resolved to output streams of other services
roverd validates a pipeline using the rovervalidate library.
Execution
When a pipeline is valid, it can be executed through roverd. All services will be executed in parallel. For each service, roverd will inject service-specific information in the runtime environment of that service using a bootspec.
Execution is halted once:
- A stop request is issued
- One service in the pipeline exits
When execution is halted, roverd will attempt to gracefully interrupt all enabled services. After 0.5 seconds, all services that are still running will receive a SIGKILL from roverd.
A pipeline's lifetime is dictated by the shortest-running service.